Here’s what you need to know.
What it is:
The emerald ash borer, commonly called EAB is a beetle native to asia, that is devastating ash trees, native to north america. as of late april of 2026 the emerald ash borer (EAB) has been officially detected or has resulted in the quarantine of 11 of maine’s 16 counties.
How does EAB spread?
EAB spreads in two main ways. The first is flight. the beetles can fly short distances from tree to tree where they tunnel under the bark to lay their larvae. this form of spreading causes a more localized problem, while the second form causes them to spread great distances rapidly, which is human movement of infested wood (firewood).
How can i slow the spread?
The maine department of agriculture, conservation and forestry have put out a best management practices (BMP) for the handling of ash wood. a link to quickly reference that BMP can be found here.
can my ash tree be treated if it has EAB?
yes, we have had success treating ash trees that have been infested with the EAB as long as there is less than 50% dieback in the canopy of the tree. injectable treatments offer the most effective control spread of the EAB and its larvae.
can i protect my ash trees that don’t have EAB?
yes! Preventive treatments are very successful and the effects of the treatments last up to two years.
what to look for
woodpeckers feed on borer beetles. they begin this process by pecking away the bark of the tree in patches while searching for beetles. this is what is known as “blonding“. while it can be unsightly, and cause significant damage to the tree, it’s usually the first indicator of a beetle infestation.
entry and exit holes. beetles make distinctly different entry and exit holes in the trunks of a tree. the shapes and sizes of these holes can help determine which pest may have created them.
distinct S-shaped tunnels under the bark, called galleries. this is where the emerald ash borer (EAB) deposits its larvae, where it will remain until it emerges two years later.
if you have questions or you are concerned you may be dealing with an infestation, please call or text us today. emerald ash borers are a serious problem and need to be handled quickly to prevent further spread.
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